The No. 1 reason the Jaguars won the AFC South and their 10-3 wild-card round game to advance to Pittsburgh was their defense. Ensuring Jacksonville hung on in the second half of a 45-42 shootout over the Steelers to advance to the franchise's first conference title game since 1999? How about Blake Bortles?
Read it again and allow it to sink in. Bortles bailed out the Jaguars ‘D,’ which allowed more than 27 points for the second time since September and third time all season, by standing toe to toe with Ben Roethlisberger and the "Killer B's" in crunch time. With the Jaguars’ unraveling seemingly imminent.
The Jaguars had tons of contributors in this crazy playoff game. Leonard Fournette rumbled for more than 100 yards and tallied a TD hat trick, gutting out what appeared to be a painful ankle injury that cut his monster first half short with a trip to the locker room. When he exited with 12 carries, 82 yards and two touchdowns, the Jaguars' tone setter was gone and the tensions were running high.

Jacksonville's O-line was heroic in not allowing Bortles to be sacked or even face much pressure. They took the fight to the Steelers' physical front.
And Marrone thoroughly out-coached two-time Super Bowl winner Mike Tomlin from the outset. The Jaguars played with urgency immediately while building a stunning 21-0 second quarter lead on the strength of forcing two Roethlisberger turnovers. Pittsburgh, though, coached an awful game, sleepwalking through the first quarter and failing to convert a pair of fourth-and-1 attempts on puzzling play calls.
Telvin Smith scooped and scored on a 50-yard return after Yannick Ngakoue’s strip-sack shortly before halftime. Marcell Dareus played stout up front. But the Jaguars' usually sensational 'D' just couldn't stop the desperate Steelers, and someone would need to step up.
While Roethlisberger posted the insane numbers — 37-of-58 for 469 yards and five touchdowns, bringing the Steelers back every time they appeared buried — it was Bortles’ poise that perhaps was most impressive. He was big on two key second-half drives that ensured Jacksonville wouldn’t be this year’s Atlanta Falcons by squandering a three-score lead against the favorites with the Hall of Famers and Super Bowl pedigree.
Bortles finished just 14-of-26 for 214 yards, one touchdown and a 94.1 rating. But his immediate responses following the Steelers’ second fourth-down failure, then an amazing Roethlisberger touchdown that cut Jacksonville’s lead to 35-28 were the ones that franchise quarterbacks must deliver.
We’re not suddenly anointing Bortles as a franchise QB, to be clear. But he certainly did plenty to at least temporarily silence some of his over-the-top critics with four consecutive clutch third-down conversions, when Jacksonville seemed to be playing not to lose.
A third-and-8 connection with Marqise Lee prevented Pittsburgh — and the Jaguars’ taxed ‘D’ — from returning immediately to the field. Bortles then hit his one deep ball of the game — a 43-yard jump ball off playaction to Keelan Cole — and Fournette scored one play later to make it 35-21.
Then, following a ridiculous Roethlisberger-Antonio Brown touchdown that almost instantly cut the lead back to one touchdown, Bortles found T.J. Yeldon on a dump-off in the flat on third-and-5, with Yeldon immediately turning upfield for 40 yards. Then, on third-and-4, Bortles found Dede Westbrook for eight yards and FB Tommy Bohanon for a 14-yard touchdown. Eight plays, 75 yards and momentum effectively stolen back in a see-saw battle.
Will a few timely plays by Bortles be enough next week in Foxborough vs. a Patriots club capable of again stressing Jacksonville's 'D?' Probably not. Still, usually the key for him is to protect the football — he's still turnover free in these playoffs — and let the Jaguars lean on Fournette and their 'D.'

Sunday, the Jaguars needed more than that. Bortles was up to the challenge, and now the Jaguars — one year removed from 3-13 — are one win from the Super Bowl.